INDIANAPOLIS -- Colts linebacker D'Qwell Jackson has been suspended without pay for the final four regular-season games for using performance enhancing substances, the NFL announced Tuesday.
Jackson will be eligible to return Jan. 2, 2017, the day after the regular season ends.
The Colts will have to make the playoffs in order for Jackson to play again this season. They're currently in a three-way tie with Houston and Tennessee for first place in the AFC South.
Jackson has led the Colts in tackles in each of his three seasons with the team. He left Monday night's game against the New York Jets with a concussion.
Middle linebacker has been a weak spot for the Colts all season. Josh McNary is a possible candidate to start while Jackson is out.